The crystal and molecular structure of the 2,4,6,8 tetra-t-Bu-phenothiazine 0.5 benzene adduct

The crystal structure of 2,4,6,8-tetra-t-Bu-phenothiazine 0.5C(6)H(6) (Pnma space group, a = 11.685, b = 25.593, c = 10.339) shows short intermolecula r t-Bu(CH3)... Ph and CH3... CH3 contacts which allow the formation of well defined channels along the a direction. These channels host one benzene mo lecule for each pair of phenothiazine molecules. AM1 molecular orbital calc ulations suggest that there is a strong coupling of the t-Bu groups rotatio ns and the folding of the ring and this in turn makes the phenothiazine ske leton to be less folded than expected from the presence of four electron do nating substituents. (C) 2000 Elsevier Science B.V. All rights reserved.